CAQ REVIEW
Femoroacetabular Impingement Annie Casta, MD Definitions & Femoroacetabular impingement (FAI) previously also called ‘‘acetabular rim syndrome’’ is a major cause of early osteoarthritis of the hip. & FAI is characterized by an early pathologic contact during hip joint motion between skeletal prominences of the acetabulum and the femur that limits the physiologic hip range of motion, typically flexion and internal rotation. & Two types:
) Cam impingement V femoral cause of FAI and is due to an aspherical portion of the femoral headneck junction (Figure A)
) Pincer impingement V acetabular cause of FAI and is characterized by focal or general over coverage of the femoral head (Figure B) Cause & Unknown V suspected to be congenital and to have genetic association or develops during periods of growth (acquired). It is likely a combination of one’s genetics and environment. Epidemiology & FAI usually affects patients in their 20s to 40s. & The estimated prevalence is 10% to 15%. & Nearly 86% have a combination of both cam and pincer impingement.
Figure: A. Cam impingement V femoral cause of FAI and is due to an aspherical portion of the femoral head-neck junction. B. Pincer impingement V acetabular cause of FAI and is characterized by focal or general over coverage of the femoral head. (Figures are courtesy of Annie Casta, MD.) Address for correspondence: Annie Casta, MD, Boston University, 908 Commonwealth Ave., Boston MA. Column Editor: John R. Hatzenbuehler, MD; E-mail: [email protected]. 1537-890X/1404/276Y277 Current Sports Medicine Reports Copyright * 2015 by the American College of Sports Medicine
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Volume 14 & Number 4 & July/August 2015
Copyright © 2015 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
CAQ Review
& Approximately 14% have pure FAI forms of either &
cam or pincer impingement. Commonly associated sports are ice hockey, soccer, ballet/dance/acrobatics, rugby, lacrosse, football, rowing, and golf.
Important Differential Diagnoses & Hip dysplasia & Lumbar spine pain (lower back pain) & Sacroiliitis (sacroiliac joint pain/dysfunction, back of pelvis) & Trochanteric bursitis (outside/lateral hip pain) & Piriformis syndrome (back of hip pain) & Psychosomatic pain disorder (stress-related illness) & Iliopsoas tendinitis/tendonitis/tendinosis (hip flexor inflammation) & Sports hernia (core muscle injury, abdominal muscle strain) & Quadriceps hernia/strain & Hamstring tendinitis/tendinosis Key Radiological Principles & X-rays V an A/P pelvic view and lateral view of the proximal femur Cam &
) The pistol grip deformity V the shape of the proximal femur in this deformity appears like pistol ) Alpha angle V also can be measured if 955- is indicative of a cam impingement
www.acsm-csmr.org
& Pincer ) Crossover or figure-of-eight sign V the posterior rim of acetabulum does not lie lateral to the anterior wall on an AP view ) Ischial spine sign V ischial spine project into the pelvis ) Posterior wall sign V femoral head lies lateral to the posterior wall ) Coxa profunda V teardrop crosses over the ilioischial line but the femoral head ) Protrusio acetabuli V both the teardrop and the femoral head cross the illioischial line Treatment & Physical therapy
) Range of motion and flexibility ) Muscle strength and endurance ) Proprioception
& Surgical
V if needed would include trimming the acetabular rim or the femoral head-neck offset either by surgical hip dislocation or arthroscopically
References 1. Ganz R, Bamert P, Hausner P, Isler B, et al. Cervico-acetabular impingement after femoral neck fracture [in German]. Unfallchirurg. 1991; 94:172Y5. 2. Ganz R, Parvizi J, Beck M, et al. Femoroacetabular impingement: a cause for osteoarthritis of the hip. Clin. Orthop. Relat. Res. 2003; 417:112Y20. 3. Klaue K, Durnin CW, Ganz R. The acetabular rim syndrome: a clinical presentation of dysplasia of the hip. J. Bone Joint Surg. Br. 1991; 73:423Y9. 4. Murphy SB, Tannast M, Kim YJ, Buly R, et al. De´bridement of the adult hip for femoroacetabular impingement: indications and preliminary clinical results. Clin. Orthop. Relat. Res. 2004; 429:178Y81.
Current Sports Medicine Reports
Copyright © 2015 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
277
Femoroacetabular Impingement Annie Casta, MD Definitions & Femoroacetabular impingement (FAI) previously also called ‘‘acetabular rim syndrome’’ is a major cause of early osteoarthritis of the hip. & FAI is characterized by an early pathologic contact during hip joint motion between skeletal prominences of the acetabulum and the femur that limits the physiologic hip range of motion, typically flexion and internal rotation. & Two types:
) Cam impingement V femoral cause of FAI and is due to an aspherical portion of the femoral headneck junction (Figure A)
) Pincer impingement V acetabular cause of FAI and is characterized by focal or general over coverage of the femoral head (Figure B) Cause & Unknown V suspected to be congenital and to have genetic association or develops during periods of growth (acquired). It is likely a combination of one’s genetics and environment. Epidemiology & FAI usually affects patients in their 20s to 40s. & The estimated prevalence is 10% to 15%. & Nearly 86% have a combination of both cam and pincer impingement.
Figure: A. Cam impingement V femoral cause of FAI and is due to an aspherical portion of the femoral head-neck junction. B. Pincer impingement V acetabular cause of FAI and is characterized by focal or general over coverage of the femoral head. (Figures are courtesy of Annie Casta, MD.) Address for correspondence: Annie Casta, MD, Boston University, 908 Commonwealth Ave., Boston MA. Column Editor: John R. Hatzenbuehler, MD; E-mail: [email protected]. 1537-890X/1404/276Y277 Current Sports Medicine Reports Copyright * 2015 by the American College of Sports Medicine
276
Volume 14 & Number 4 & July/August 2015
Copyright © 2015 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
CAQ Review
& Approximately 14% have pure FAI forms of either &
cam or pincer impingement. Commonly associated sports are ice hockey, soccer, ballet/dance/acrobatics, rugby, lacrosse, football, rowing, and golf.
Important Differential Diagnoses & Hip dysplasia & Lumbar spine pain (lower back pain) & Sacroiliitis (sacroiliac joint pain/dysfunction, back of pelvis) & Trochanteric bursitis (outside/lateral hip pain) & Piriformis syndrome (back of hip pain) & Psychosomatic pain disorder (stress-related illness) & Iliopsoas tendinitis/tendonitis/tendinosis (hip flexor inflammation) & Sports hernia (core muscle injury, abdominal muscle strain) & Quadriceps hernia/strain & Hamstring tendinitis/tendinosis Key Radiological Principles & X-rays V an A/P pelvic view and lateral view of the proximal femur Cam &
) The pistol grip deformity V the shape of the proximal femur in this deformity appears like pistol ) Alpha angle V also can be measured if 955- is indicative of a cam impingement
www.acsm-csmr.org
& Pincer ) Crossover or figure-of-eight sign V the posterior rim of acetabulum does not lie lateral to the anterior wall on an AP view ) Ischial spine sign V ischial spine project into the pelvis ) Posterior wall sign V femoral head lies lateral to the posterior wall ) Coxa profunda V teardrop crosses over the ilioischial line but the femoral head ) Protrusio acetabuli V both the teardrop and the femoral head cross the illioischial line Treatment & Physical therapy
) Range of motion and flexibility ) Muscle strength and endurance ) Proprioception
& Surgical
V if needed would include trimming the acetabular rim or the femoral head-neck offset either by surgical hip dislocation or arthroscopically
References 1. Ganz R, Bamert P, Hausner P, Isler B, et al. Cervico-acetabular impingement after femoral neck fracture [in German]. Unfallchirurg. 1991; 94:172Y5. 2. Ganz R, Parvizi J, Beck M, et al. Femoroacetabular impingement: a cause for osteoarthritis of the hip. Clin. Orthop. Relat. Res. 2003; 417:112Y20. 3. Klaue K, Durnin CW, Ganz R. The acetabular rim syndrome: a clinical presentation of dysplasia of the hip. J. Bone Joint Surg. Br. 1991; 73:423Y9. 4. Murphy SB, Tannast M, Kim YJ, Buly R, et al. De´bridement of the adult hip for femoroacetabular impingement: indications and preliminary clinical results. Clin. Orthop. Relat. Res. 2004; 429:178Y81.
Current Sports Medicine Reports
Copyright © 2015 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
277
